title: Assessment of body composition by bioelectrical impedance in a population aged greater than 60 y.
abstract: Body composition was measured in a group of 35 healthy men and 37 healthy women aged 60-83 y. Body mass index (BMI) in men was 25.0 +/- 2.2 kg/m2 (means +/- SD) and in women, 25.9 +/- 3.2 kg/m2. BMI was low in relation to body fat percentage as determined by skinfold-thickness measurements or densitometry in comparison with the relation found in younger adults. Mean body fat percentage of the male subjects (aged 70.4 +/- 5.2 y) as determined by densitometry was 31.0 +/- 4.5%, whereas in women (aged 68.0 +/- 5.2 y) it was 43.9 +/- 4.3%. Body impedance correlated with fat-free mass (FFM). The best prediction formulas for the FFM from body impedance and anthropometric variables were 1) FFM (kg) = (0.671 x 10(4) x H2/R) + 3.1S + 3.9 where H is body height (m), R is resistance (omega), and S is gender (females, 0; males, 1) (r = 0.94; SEE = 3.1 kg) and 2) FFM (kg) = (0.360 x 10(4) x H2/R) + 0.359BW + 4.5S - 20T + 7.0 where BW is body weight (kg) and T is thigh circumference (m) (r = 0.96; SEE = 2.5 kg). The prediction equations from the literature, generally determined in younger populations, overestimated FFM in elderly subjects by approximately 6 kg and are not applicable to elderly subjects.
authors.affiliation: Department of Human Nutrition, Wageningen Agricultural University, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Deurenberg
authors.forename: K
authors.initials: K
authors.lastname: van der Kooij
authors.forename: P
authors.initials: P
authors.lastname: Evers
authors.forename: T
authors.initials: T
authors.lastname: Hulshof
mesh_terms: D000273:Adipose Tissue; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D004553:Electric Conductivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012044:Regression Analysis; D012885:Skinfold Thickness